Drinking tumbler



FIG. 1 is a top, side and front perspective view of a drinking tumbler showing my new design;

FIG. 2 is a front elevation view, the rear and side elevations being identical thereto;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof.

The broken line portions of FIGS. 3 and 4 form no part of the claimed design. 

The ornamental design for a drinking tumbler, as shown and described. 